Wearable technology such as smart clothing fuses textiles and electronics to make a wearer's life easier by implementing different aspects of ubiquitous computing for both private and business purposes. Recent advancements in material technology and miniaturization have brought forward solutions that the users have only dreamed about a decade or two ago. Hard shell wearable technology such as various smart watches or generally wristop devices has been limitedly available for some time now starting from the 80's wristop calculator watches evolving into sports/fitness computers, activity monitors and most recently, various communications-enabled apparatuses approaching e.g. cell phones and tablets in terms of embedded features. Yet, few wearable smartglasses and e.g. personal security—related products have since hit the markets.
E-textiles or ‘smart textiles’ refer to fabrics that provided for integration with electronics such as sensory integration. The e-textiles may incorporate both electrically conductive materials, such as conductive yarn, and insulating materials for providing the desired electrical properties to the components embedded therewithin.
Also footwear such as shoes, boots, socks, insoles, etc. may benefit from the advent of wearable electronics and smart clothing. As with other garments, the footwear may be provided with integrated electrical components such as processor, memory, communication interface, and a sensor.
FIG. 1 illustrates one example of a possible multilayer structure 100 for constructing smart insoles or soles for shoes provided with a sensing functionality. The various layers of the structure have been depicted as physically separate from each other for clarity purposes only.
The structure 100 may incorporate a base part or base substrate 102 that may be provided with electronics. For instance, the base 102 may be provided with recesses for accommodating electronic components. Further layers are provided onto the base. Such layers include insulation layers 104, 108 and sensing layers 106, 110 that together form a pressure sensor. Protective layers 112 may be provided on top to protect the underlying features from potentially detrimental effects of the environment such as external impacts, moisture, dirt, etc. The established sensor detects capacitance change due to a pressure imposed on the multilayer structure by the foot of the wearing person, hereinafter user, causing compression of e.g. the insulating layer 108 between the sensing layers 106, 110. The distance between the layers 106, 110 acting as capacitor plates is thus responsive to the pressure and affects the sensed capacitance between the plates. Perhaps even in a greater majority of similar products, separate force-sensitive resistive sensors have been deployed for sensing the pressure caused by the user's movements.
Notwithstanding the various functional benefits the above-described sole structure may admittedly offer over a variety of more traditional passive insoles having regard to e.g. monitoring capability of mechanical pressure induced thereto, there still seems to remain some room for improvement.
The obtained structure may easily turn out somewhat stiff and thick, which is understandable when a considerable number of material layers having electronic components, conductors, etc. embedded therewith are joined together with necessary electrical, insulation, accommodation and protective capabilities, but still undesirable in terms of a limited space available in the target footwear and user discomfort arising from the material selections and related parameters such as stiffness/rigidity and even weight.